"Within hours of Weiner’s public confession Monday, House Minority Leader Nancy Pelosi (D-Calif.) called on the Committee on Standards of Official Conduct, as the ethics panel is formally known, to launch an investigation. The panel issued a statement the next day, saying, “If and when an investigation is appropriate in any matter, the committee will carry out its responsibilities pursuant to our rules.”

But which rules, exactly?

The word “Twitter” does not appear in the House Code of Official Conduct, nor does “direct message” or “explicit photo.” Infidelity is not referenced, either, and while the means of communication may be new, lawmakers have generally been wary of policing each other’s sexual behavior.

“If the only evidence out there . . . clearly indicated that this was personal conduct only between consenting adults, I just don’t see a reason why the ethics committee would or should take it up,” said Robert L. Walker, the former staff director of both the House and Senate ethics panels. “Even if people think it’s reprehensible conduct, that doesn’t mean it’s an ethics violation.”

The House does have guidelines governing “official electronic communication content,” and rules permitting lawmakers to post content on external Web sites for “official purposes,” but it’s not clear whether Weiner’s Twitter account falls under those categories."